Cannot sample enough valid points. (more)

\[\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)\]
\left(\left(\left(\sqrt{x + 1} - \sqrt{x}\right) + \left(\sqrt{y + 1} - \sqrt{y}\right)\right) + \left(\sqrt{z + 1} - \sqrt{z}\right)\right) + \left(\sqrt{t + 1} - \sqrt{t}\right)
double f(double x, double y, double z, double t) {
        double r22331638 = x;
        double r22331639 = 1.0;
        double r22331640 = r22331638 + r22331639;
        double r22331641 = sqrt(r22331640);
        double r22331642 = sqrt(r22331638);
        double r22331643 = r22331641 - r22331642;
        double r22331644 = y;
        double r22331645 = r22331644 + r22331639;
        double r22331646 = sqrt(r22331645);
        double r22331647 = sqrt(r22331644);
        double r22331648 = r22331646 - r22331647;
        double r22331649 = r22331643 + r22331648;
        double r22331650 = z;
        double r22331651 = r22331650 + r22331639;
        double r22331652 = sqrt(r22331651);
        double r22331653 = sqrt(r22331650);
        double r22331654 = r22331652 - r22331653;
        double r22331655 = r22331649 + r22331654;
        double r22331656 = t;
        double r22331657 = r22331656 + r22331639;
        double r22331658 = sqrt(r22331657);
        double r22331659 = sqrt(r22331656);
        double r22331660 = r22331658 - r22331659;
        double r22331661 = r22331655 + r22331660;
        return r22331661;
}